MONDAY, June 24 (HealthDay News) -- The antibiotic Vibativ (telavancin) has been approved by the U.S. Food and Drug Administration to treat pneumonia caused by Staphylococcus aureus bacteria when other treatments aren't suitable.

Pneumonia, a lung infection, can be caused by different bacteria and viruses. S. aureus infection often affects people in hospitals, notably those on ventilators. Such infections can be serious, since people on a ventilator often have a weakened immune system and are unable to fight an infection, the FDA said in a news release.

Vibativ's safety and effectiveness were evaluated clinically among 1,532 people. The studies found the drug was about as effective in treating S. aureus pneumonia as another approved antibiotic, vancomycin.

However, the studies found that more people treated with Vibativ died if they also had kidney problems, compared to kidney patients who took vancomycin. The FDA said it would add this information to Vibativ's label. The most common clinical side effect of Vibativ is diarrhea.

Vibativ was first approved in 2009 to treat skin infections. The drug is marketed by San Francisco-based Theravance Inc.